If you are having guests visit you for the holidays, whether it be your adult children, your parents, your siblings, your friends,your grandparents or your favorite aunt or uncle, one way to politely help them pay for the trip is to give them a gas visa card.  You can buy these cards at a discount from the face price from people who got them as a promotion or gift and want to sell them for cash.  You can also get them in combination with another purchase.  This method of payment for gas is a lot more polite than just giving cash and they make great stocking stuffers.